Tetrazine

From Memory Alpha, the free Star Trek reference.

Tetrazine is a highly volatile gaseous substance that is a by-product of the mining operations of the colony on Paraagan II. A tetrazine reaction with electro-plasma was responsible for the colony's destruction in 2152.

Tetrazine settles between forty-five and fifty kilometers high in the atmosphere. Plasma exhaust is one of the few things hot enough to ignite tetrazine, and thus approaching spacecraft are required to close their exhaust ports. Borocarbons result from the reaction between plasma and tetrazine. (ENT: "Shockwave")

Tetrazine is a real compound (C₂H₂N₄) which may be regarded as benzene with four CH groups replaced by nitrogen atoms.